1. Field of the Invention
The invention relates to object sensing apparatus and more particularly to the utilization thereof in automatic swing door mechanisms.
2. State of the Prior Art
Although automatic swing door mechanisms are well known and in extensive use, the patent art relative thereto is rather limited. U.S. Pat. Nos. 1,929,273, 3,852,592 and 4,467,251 appear to represent the best art having a bearing on the present invention, but only U.S. Pat. No. 4,467,251 incorporates means relating to safety in connection with the swing side of the automatic door structure. The present invention, while directed to a similar basic idea, incorporates distinct variations in the type of structure employed and the comparative mode of operation thereof. Particularly, this invention employs the well known and used microwave beam principle as the primary means of object detection, together with controlled circuitry for easily and effectively achieving most desirable results.